How severe is CVE-2021-36226?

CVE-2021-36226 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-36226 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36226?

CVE-2021-36226 affects Westerndigital My Cloud Os. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-36226?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-36226 published?

CVE-2021-36226 was published on 2023-02-06 and last updated on 2026-06-17.

CVE-2021-36226

CVE-2021-36226 is a critical-severity vulnerability in Westerndigital My Cloud Os with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Westerndigital My Cloud Os
Published: 2023-02-06
Last modified: 2026-06-17

Description

Western Digital My Cloud devices before OS5 do not use cryptographically signed Firmware upgrade files.

Frequently asked questions

What is CVE-2021-36226?: Western Digital My Cloud devices before OS5 do not use cryptographically signed Firmware upgrade files.
How severe is CVE-2021-36226?: CVE-2021-36226 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-36226 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36226?: CVE-2021-36226 affects Westerndigital My Cloud Os. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-36226?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-36226 published?: CVE-2021-36226 was published on 2023-02-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:westerndigital:my_cloud_os:*:*:*:*:*:*:*:*

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